Description

What's New

TI speeds ultrasound design and reduces board space by more than 50% with the TX810, the industry's first integrated transmit/receive switch

Similar to the fixed Ultrasound systems, portable ultrasound systems use an array of receivers to build an image by time shifting, scaling, and intelligently summing echo energy. However, the challenge with developing a portable system is maintaining a acceptable image quality while achieving portability in terms of size and runtime. Often this is accomplished by reducing the number of channels used in the device, trading off image quality and information for a reduction in power consumption and size.

The concept of time shifting and scaling, which is based on receiving signals from a transducer array, provides the ability to "focus" on a single point in the scan region. By subsequently focusing at different points, an image is assembled. Using more integrated solutions can help increase signal integrity and reliability. Using a HV pulsar which integrates the DAC, a low pass filter as well as an amplifier is an example of this, simplifying the filtering requirements and reducing the noise in the transmit signal chain. Likewise using the complete integrated analog portable ultrasound receive frontend reduces the noise and the number of components needed to support the channels used in the design.

Since the output is graphical in nature the use of a touch screen as an interface would allow for a large display while maximizing the use of space to ensure a smaller form factor. Using multiple TI DSPs like a C64XX coupled with an OMAP35XX would allow for a completely integrated backend. In addition to having a powerful core for video acceleration for the graphics display, a Cortex A8 processor will help to handle the management of the OS and touch screen interface which helps keep power consumption down by allowing for one of the processors to be powered down while not in use as well as eliminating another sub system. To compensate for the reduction of channels, post processing can be done to the image by delaying the image display while collecting more dada to render. This would give a more accurate image while trading off the ability to see the image in real-time as well as power consumption on the processor.

Power and Battery Management are key in this system, where key design considerations are ultra-low power consumption and high efficiency driven by the need for extended battery life, and high precision. Additional requirements may drive the need for recording the images, cabled or wireless interfaces for transmission of the images. Also, to enable ease of use, features like touch screen control and display backlighting are key to usability of the device. Adding all these features without significantly increasing power consumption is a huge challenge. Being a medical device it is also important to be able to monitor the amount of power left in the device. Texas Instruments portfolio of Processors, Instrumentation and Buffer Amplifiers, Power and Battery Management such as Impedance tracking and gas gauging, Audio Codecs, and both wired and wireless interface devices provides the ideal tool box for this system.